Abstract

This essay offers a new interpretation of Nietzsche's argument for moral skepticism (i.e., the metaphysical thesis that there do not exist any objective moral properties or facts), an argument that should be of independent philosophical interest as well. On this account, Nietzsche offers a version of the argument from moral disagreement, but, unlike familiar varieties, it does not purport to exploit anthropological reports about the moral views of exotic cultures, or even garden-variety conflicting moral intuitions about concrete cases. Nietzsche, instead, calls attention to the single most important and embarrassing fact about the history of moral theorizing by philosophers over two millennia: namely, that no rational consensus has been secured on any substantive, foundational proposition about morality. Persistent and apparently intractable disagreement on foundational questions, of course, distinguishes moral theory from inquiry in the sciences and mathematics (perhaps in kind, certainly in degree). According to Nietzsche, the best explanation for this disagreement is that, even though moral skepticism is true, philosophers can still construct valid dialectical justifications for moral propositions because the premises of different justifications will answer to the psychological needs of at least some philosophers and thus be deemed true by some of them. The essay concludes by considering various attempts to defuse this abductive argument for skepticism based on moral disagreement and by addressing the question whether the argument "proves too much," that is, whether it might entail an implausible skepticism about a wide range of topics about which there is philosophical disagreement.